London Home Extensions · Vetted Builders · No-Obligation Quotes

Turn your house extension ideas into a fixed, free quote

Our bespoke design and build service covers kitchen extensions, side return, rear, wraparound, double storey extensions and loft conversions — matching you with a vetted London builder and delivering a fixed, transparent quote at no cost to you.

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What We Cover

Extension types we specialise in

Every London home is different. From the Victorian terraced house in Islington to the semi-detached in Ealing, we'll help you find the right extension for your property and budget.

Modern rear extension on a London terraced house

Rear Extension

A rear extension projects outward into your back garden, typically adding a larger kitchen, open-plan kitchen-diner or family room — ideal open plan living space for a growing family. It's the most popular choice for London homeowners looking to gain meaningful space without touching the front of the property. Larger open-plan spans will typically require a steel beam for structural support — our builders will advise you on this during the site visit. Suits most house types.

Popular choice
Side return kitchen extension with skylights and open-plan layout

Side Return Extension

Many London terraced houses have a narrow, underused alley running alongside the kitchen — the side return. Infilling this space extends the kitchen width dramatically, letting in more natural light and creating a proper open-plan layout. It's one of the best-value transformations available to Victorian and Edwardian terraced houses across London. Because side return and rear extensions on terraced houses often adjoin a neighbouring property, our network also helps homeowners navigate party wall agreements before work begins.

Perfect for terraces
Wraparound extension creating large open-plan kitchen and living space

Wraparound Extension

A wraparound combines a rear and side return extension into one L-shaped structure, creating the largest possible ground-floor footprint. The result is a generous open-plan kitchen and living area that transforms how the whole ground floor feels. Larger structural spans across this combined space commonly require a steel beam. Suits semi-detached and end-of-terrace properties.

Maximum space gain
Double storey rear extension on a London family home

Double Storey Extension

Going up as well as out, a double storey extension adds significant space on both ground and first floors — typically a larger kitchen below and one or two bedrooms (often with an en suite) above. A well-designed double storey adding a bedroom and bathroom can add 15–20% to a London property's value. It's a major project that almost always requires full planning permission, but the return on investment is typically the strongest of any extension type.

Best ROI
Modern kitchen extension with bifold doors and kitchen island

Kitchen Extension

A kitchen extension focuses the added space around the heart of the home — creating a kitchen-diner, open-plan family room or a properly sized cooking space that the original house simply couldn't offer. A kitchen-diner rear extension typically adds 5–10% to a London property's value and is one of the most popular projects we quote for. Suitable for a wide range of property types and budgets.

Most requested
Loft conversion bedroom with dormer window and natural light

Loft Conversion

Converting an unused loft into a bedroom, home office or bathroom is one of the most cost-effective ways to add space and value. The three main types are: Dormer (the most popular — adds a box structure to the rear slope); Hip-to-Gable (extends the sloping hip roof into a vertical gable, great for semi-detacheds); and Mansard (a flat-roofed, rear-facing conversion popular in conservation areas). Many loft conversions fall under permitted development.

Dormer · Hip-to-Gable · Mansard
Garage conversion turned into a bright home office or playroom

Garage Conversion

If you have an existing integral or attached garage, converting it into usable living space — a home office, playroom, gym or spare bedroom — is often the most straightforward and affordable way to add a habitable room. Garage conversions typically fall under permitted development and avoid the complexity of a full structural build. A practical choice for families needing an extra room without extending the footprint.

No new footprint needed
Our network builders also carry out structural alterations — including removing internal walls and installing steel beams — and bathroom renovations alongside extension projects, so you won't need a separate contractor for those finishes.
Why Work With Us

A straightforward process, with builders you can trust

Vetted builders, every time

Every builder in our network is checked for valid public liability insurance, relevant qualifications and a consistent record of completed work before they're introduced to any client.

Free, no-obligation quote

Your site visit and written quote cost you nothing. There's no pressure and no obligation — if the quote isn't right for you, you're free to walk away.

One point of contact

A dedicated project manager oversees the build team from start to finish. From your first enquiry through to completion, you'll deal with the same person throughout the build — no handoffs, no chasing, no confusion about who's responsible for what.

Fixed price before work starts

Your quote is fixed and agreed in writing before any work begins. Barring genuinely unforeseen structural changes (discussed openly if they arise), the price you see is the price you pay.

The Process

How it works

Four straightforward steps from first contact to build day.

01

Tell us about your project

Fill in the short form below — just a few details about your home, the type of extension you're considering and your rough location.

02

Free site visit and consultation

A vetted builder visits your property at a time that suits you, takes measurements, discusses your ideas and answers your questions — at no cost.

03

Fixed quote, no hidden costs

You receive a clear, written fixed-price quote covering the work discussed — with no vague allowances or surprise additions tucked in the small print.

04

Build starts on an agreed timeline

Once you're happy with the quote, a start date is agreed and confirmed in writing — so you know exactly when work will begin.

Budget Planning

Cost & timeline guide

The figures below are typical UK market ranges to help you plan — your fixed quote may vary based on specification, site conditions and location within London.

Rear Extension
£40,000 – £80,000
Typically £2,500–£3,500 / m²
10–16 weeks on site
Side Return
£35,000 – £65,000
Typically £2,500–£3,500 / m²
8–12 weeks on site
Wraparound
£60,000 – £100,000
Typically £2,800–£3,800 / m²
12–18 weeks on site
Double Storey
£70,000 – £150,000
Typically £2,800–£4,000 / m²
14–24 weeks on site
Total project timeline

The on-site build is only part of the picture. Including design drawings, planning permission (where required) and any pre-construction surveys, the full project from enquiry to completion typically runs 6–12 months. Starting the conversation early gives you the best chance of moving at your own pace.

Adding value to your property

A well-designed London extension can add 10–20% to your property's value. A kitchen-diner rear extension typically adds 5–10%, while a double storey extension adding a bedroom and bathroom can add 15–20% — often making the project cost-neutral or better over a medium-term hold.

Common Questions

Frequently asked questions

Many extensions — particularly single-storey rear extensions and some loft conversions — fall under Permitted Development (PD) rights, which means you may not need to submit a full planning application. PD rules allow single-storey rear extensions of up to 4 metres on detached houses and 3 metres on semi-detached or terraced houses (subject to conditions). Some loft conversions with dormers also qualify under PD.

However, a full planning application is typically required if your property is in a conservation area, is a listed building, has already used its PD allowance, or if the project exceeds PD limits — as is common with double storey extensions and most wraparound extensions. We'll guide you through what's likely to apply to your property during the free site visit.

The on-site build for a typical London extension runs anywhere from 8 weeks (a straightforward side return) to 24 weeks (a larger double storey project). However, the build is only one part of the timeline. When you include architectural drawings, the planning application and decision period (typically 8 weeks), and any pre-construction groundwork, the full project from first enquiry to completion typically takes 6–12 months. The site visit will give you a more accurate estimate for your specific project.

Yes — completely. The site visit, the consultation and the written fixed-price quote are all provided at no cost to you. There is no obligation to proceed, and we will never pressure you into a decision. If the quote isn't right for your project or budget, you're entirely free to walk away.

Our network covers all areas of London — North, South, East, West, South West and Central. This includes most London boroughs and postcodes. If you're unsure, simply fill in your postcode in the quote form and we'll confirm whether we can help. We cover a wide area and rarely turn an enquiry away on location alone.

Your quote will typically cover all structural build work, materials, labour, and site management for the agreed scope of works. It will set out exactly what is and isn't included so there are no surprises. Items like kitchen fitting, bespoke joinery and interior decoration are typically scoped separately and clearly itemised. We'll talk through the full scope during the site visit so your quote is as accurate and complete as possible.

Yes — combining a loft conversion with a ground-floor extension is a common and practical approach. Running both projects simultaneously (or in close sequence with the same builder) typically reduces overall disruption and can be more cost-effective than two separate contracts. Many homeowners choose to add a rear or side return extension at ground level while converting the loft into a bedroom or bathroom above. We'll discuss what works best for your property and phasing during the site visit.

In most cases, yes — the majority of homeowners remain in their property throughout the build. A well-run build team will work in a way that minimises disruption to your daily routine: sealing off the work area, maintaining access to key rooms, and keeping the site safe and tidy throughout the build. That said, there will be noisier and dustier phases — particularly early groundworks and steelwork — and your project manager will keep you informed of what to expect week by week. If your project involves significant structural work to the existing house, such as removing a rear wall, your team will discuss the most practical approach with you in advance.

Start Here

Get your free, fixed-price quote

Tell us a little about your project and we'll arrange a free site visit at a time that suits you. No obligation, no pressure.

Where We Work

Areas covered across London

Our network of vetted builders covers all London boroughs and postcodes across the capital. Below are the main areas we work in — if your postcode isn't listed, get in touch and we'll confirm whether we can help.

North London
BarnetFinchleyIslingtonCamdenHampsteadMuswell HillCrouch End
South London
ClaphamWandsworthBalhamStreathamBrixtonLewisham
South West London
FulhamRichmondPutneyWimbledonTwickenham
West London
EalingChiswickActonHammersmithKensington
East London
HackneyTower HamletsWalthamstowStratfordBow
Central London
WestminsterSouthwarkLambethCity

Not sure if we cover your area? Submit your postcode in the quote form — we'll confirm within one working day.